398 GENETICS IN RELATION TO AGRICULTURE 



of seed potatoes. It is transmitted through the seed. (4) It is doubtful if any 

 method of seed selection will prevent the "running out" of seed potatoes under 

 certain conditions." 



Other Crops in Which Bud Selection May Apply. It is claimed that 

 many desirable varieties of roses, carnations, chrysanthemums, violets 

 and other plants which are cultivated for their flowers originated as 

 bud sports. The best florists are very critical regarding the character- 

 istics of their stock and sports are soon discovered. The importance of 

 propagating from typical, healthy plants is generally appreciated. 

 Many of the roses used for forcing winter blooms produce two types of 

 shoots which are known to the horticulturist as blind and flowering 

 wood. For some years the Bureau of Plant Industry conducted ex- 

 periments on the selection of buds from the two types of shoots, but it 

 became apparent that the diversity among individual plants in regard 

 to their flowering habits, whether propagated from blind or from flowering 

 wood, was greater than the diversity between the progeny of flowering 

 wood plants as compared with the progeny of blind wood plants. As a 

 result of fertilizer experiments with the variety, My Maryland, Blake 

 inferred that there was a real basis for production of improved strains 

 by bud selection. But he points out that it would require time and much 

 care in selection and that the average florist can hardly attempt to do 

 more than to note the relative vigor of his plants at various stages and 

 propagate from the best producers that are not especially favored by 

 particular environmental conditions. 



The strawberry is so important commercially and comes into bearing 

 so soon when propagated from offsets that if bud selection were effective 

 in producing improved strains it would be of tremendous practical value. 

 But the results of experiments indicate that the individual differences so 

 frequently observed in strawberry plants are merely modifications. Whit- 

 ten reports that bud selection of strawberry plants during a period of 

 15 years has given no gain in the total productiveness of the plots 

 which originated from high-productive plants over the plots which 

 originated from low-productive plants of the same variety. The experi- 

 ment began by selecting six plants that yielded four times the amount of 

 fruit of six low-producing plants all of the Aroma variety. Each 

 succeeding year selections in the high-yielding plot were made from the 

 highest plants and in the low-yielding plot from lowest-yielding plants. 

 It is possible that in some varieties of strawberries bud mutations occur 

 more frequently than in others. But in order to find a high-yielding 

 plant whose high-producing character would be maintained among its 

 vegetative offspring it would probably be necessary to test hundreds of 

 individual high-producing plants. Hybridization offers much greater 

 promise in the production of high-yielding strains of strawberries. 



